Pharmaceutical Suspensions

The suspension dosage form has long been used for poorly soluble active ingredients for various therapeutic indications. Development of stable dispersions over the shelf life of the drug product continues to be a challenge on many fronts.A good understanding of fundamentals of disperse systems is essential in the development of a suitable pharmaceutical suspension. The development of suspension dosage form follows a very complicated path. The selection of the proper excipients (surfactants, viscosity imparting agents etc.) is important. The particle size distribution in the finished drug product dosage form is a critical parameter that significantly impacts the bioavailability and pharmacokinetics of the product. Appropriate analytical methodologies and instruments (chromatographs, viscometers, particle size analyzers, etc.) must be utilized to properly characterize the suspension formulation. The development process continues with a successful scale-up of the manufacturing process. Regulatory agencies around the world require clinical trials to establish the safety and efficacy of the drug product. All of this development work should culminate into a regulatory filing in accordance with regulatory guidelines. Pharmaceutical Suspensions, in its organization, follows the development approach used widely in the pharmaceutical industry. The primary focus of this book is on the classical disperse system – poorly soluble active pharmaceutical active dispersed in a suitable vehicle.After discussing various disperse systems, the theory of disperse systems and commonly used excipients, the remaining chapters in this textbook systematically detail the development of pharmaceutical suspensions, from pre-formulation stage to clinical development, regulatory submission and commercial manufacturing. Additionally, the emerging area of nano-suspensions as applied to pharmaceutical filed is also discussed. Each of the chapters in Pharmaceutical Suspensions was written independently by scientists skilled in their specific areas. Contributing authors represent a cross-sections of scholars from Academic Institutions, Pharmaceutical Industries and Regulatory Agency.

ALOK K. KULSHRESHTHA, Ph.D., Associate Director, Pharmaceutical Technology at Alcon Research Ltd., Fort Worth, Texas, has 20 years of experience in the development of sterile ophthalmic, contact lens care, and dry eye products. During this tenure in pharmaceutical industry, Dr. Kulshreshtha has worked on several suspension drug products in different stages of development. Dr. Kulshreshtha’s interest in the suspension area started almost 30 years ago when he began his doctoral dissertation on suspension rheology. Over the years, Dr. Kulshreshtha has worked on many new technologies for producing sterile suspensions. Dr. Kulshreshtha is the inventor/co-inventor of several Patents and has authored many peer reviewed publications. Dr. Kulshreshtha is a member of the American Association of Pharmaceutical Scientists (AAPS) and has been reviewer for AAPS abstracts screening for posters and symposia. Dr. Kulshreshtha holds a Ph.D. and M.S. in Chemical Engineering from Purdue University, and a Bachelor’s degree in Chemical Engineering from the Indian Institute of Technology, Kanpur, India.ONKAR N. SINGH, Ph.D., M.B.A., Assistant Director, Development at Alcon Research Ltd., Fort Worth, Texas, has over 16 years of pharmaceutical product research and development of nasal, sterile ophthalmic, sterile otic, and parentral products. Dr. Singh is inventor/co-inventor of many patents related to formulations, process and formulation technology and has authored several peer reviewed articles. Prior to joining Alcon Inc., Dr. Singh was Manager at Access Pharmaceuticals, Dallas, Texas, leading efforts in the area of site specific targeted drug delivery systems for diagnostic and therapeutic areas of cancer therapy. At Access Pharmaceuticals, Dr. Singh worked on nanoparticles, liposomes, emulsion formulations, protein pharmaceuticals and gene delivery technology. Dr. Singh served as Secretary/Treasurer of the Ocular Focus Group of AAPS from 2002 to 2005 and has been a reviewer for AAPS abstracts, posters and symposia. Dr. Singh is a member of the American Association of Pharmaceutical Scientists (AAPS). Dr. Singh currently serves as an editorial board member of American Pharmaceutical Review Journal. Dr. Singh holds a B.S. in Pharmacy, M.S. in Pharmaceutics from Banaras Hindu University, India; Ph.D. in Pharmaceutics from University of Illinois at Chicago and M.B.A. from University of Texas at Arlington, Texas.G. MICHAEL WALL, Ph.D., Senior Director of Pharmaceutical Products Development at Alcon Research, Ltd., Fort Worth, Texas, has over 21 years of pharmaceutical industrial experience in the development of intranasal, sterile ophthalmic and otic drug products. Dr. Wall is author or co-author of 2 patents and over 100 publications including peer-reviewed articles, abstracts, book chapters, book supplements and one book. Dr. Wall has led international, multidisciplinary teams in the development and approval of in the development and approval of CiprodexR Sterile Otic Suspension and PatanaseR Nasal Spray, as well as other products in countries around the world. Dr. Wall is a Scientific Fellow of the American Academy of Otolaryngology – Head and Neck Surgery. He has also served the American Chemical Society as a member for 30 years. Dr. Wall received a B.S. degree in chemistry from Auburn University, a M.S. degree in medicinal chemistry from Auburn University School of Pharmacy, a Ph.D. in medicinal chemistry from the University of Mississippi School of Pharmacy, and completed the Advanced Management Program (168th session) of the Harvard Business School.